Check one-time secret status

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=true; the description adds substantial context beyond that: the operation is non-consuming, it requires creator credentials (receiptToken, not just the link), it enumerates the possible status outcomes and their meanings, and it notes the call is free. This is rich behavioral disclosure for a read-only tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the core action and its key non-destructive property, followed by return shape, then usage routing, then the constraint, then a one-word cost note. Every clause earns its place; no padding.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema present, the description compensates by documenting the return payload shape ({ status, expiresAt, readAt? }) and the meaning of each status value. Combined with the precondition and sibling routing, an agent has everything needed to call this correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so both parameters are already documented, but the description adds semantic meaning the schema repeats only implicitly ('only works for secrets you created (needs their receiptToken)'), clarifying why the token is required and who holds it. That is a genuine increment over the baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Check whether a secret ... has been opened') with the critical qualifier 'without consuming it'. It explicitly distinguishes itself from ncrypted_read (opening a link) and ncrypted_burn, so an agent can route correctly without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives concrete when-to-use guidance ('confirm delivery, or before deciding to ncrypted_burn a link'), an explicit precondition ('Only works for secrets you created (needs their receiptToken)'), and names the alternative tool for the other use case (ncrypted_read). Nothing is left to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.